I ran some tests on the SDHC cards I’m currently using with my Canon XSi/450D. I tested the number of simultaneous RAW shots that each card was able to handle as well as the number of shots I could fire in 10secs. The RAW burst turned out to be 6 for all cards, which tells me that’s the limit of the XSi’s internal buffer. More cards are tested on Rob Galbraith’s page.

Update 8/29/08: PNY Optima Pro 8GB results posted. I ordered the PNY Optima Pro 8GB Class 6 card, and am disappointed in the results as it came in tied for last among my other cards. Perhaps the 2GB card Rob tested is better performing. I’ll have to try a SanDisk Extreme III 8GB next.

Update 9/16/08: AData Turbo 8GB Class 6 results posted. This has been the worst card of the bunch. It struggles to complete the 6 RAW shots and pulls off only 8-10 saves in the 10sec test period.

Update 9/23/08: SanDisk Extreme III 8GB Class 6 30MB/s Edition results posted. You can’t beat the SanDisk. It performed as its 4GB brother did – it wanted to get a 7th RAW burst frame, but just couldn’t make it. I’m definitely at the limits of the camera — a faster writing camera could take more advantage of the speed this card allows.